Ashita mo Kitto Koishiteru

From JShoujo Scans: MITSUKI is on top of the world when IMAI, her former tutor and sisters friend, agrees to begin dating her. Even with the seven year age gap, shes determined to make it work, even though she hardly ever gets to see him. But her happiness slowly gives way to doubts when a year passes without ever breaking down the barrier she feels between them. Does Imai-san even like her at all? Or is the person hes really in love with her older sister and hes just going out with her because he didnt have the heart to turn her down? Maybe he doesnt take her seriously because shes still in high school? When shes with him, he always seems more of the serious type—but what is this about his playboy past?!